The present invention relates to a centrifugal fan runner equipped with backward blades, and in particular relates to a cleaner fan of high efficiency, a large air volume and a low noise, an air conditioning apparatus, and an air blowing and ventilation fan.
A conventional centrifugal fan runner equipped with backward blades is described, for example, in Japanese Patent Laying-Open No. Hei 6-257595 (1994).
In the conventional centrifugal fan runner equipped with the backward blades, if a blade angle is increased for the purpose of increasing air volume to be blown out therewith, airflow collides upon a pressure surface of the blade at an inlet of the fan, thereby showing a tendency to increase noises. Also, a swirl portion of the airflow is increased at an outlet of the fan, thereby bringing about a phenomenon of reducing fan efficiency.
An object according to the present invention is, for dissolving the problem mentioned above, to provide a centrifugal fan runner, an air cleaner, and an outdoor machine of a fan, equipped with backward blades being able to increase an air volume to be blown out therewith, but without decreasing the fan efficiency thereof, even if an outer diameter thereof is almost same.
For achieving the object mentioned above, according to the present invention, there is provided a centrifugal fan runner, comprising:
a core plate being connected to an axis of a motor; and
a side plate being provided opposing to said core plate, wherein backward blades, being inclined in an anti-rotational direction thereof, are provided at a distance in a circumferential direction, being characterized in that
the backward blades are bent in a position at distance of about xc2xd-1/(3.5) of a length of the blade from an outer periphery thereof, so that an outlet portion thereof is inclined into a direction of rotation of the blade, and an outlet angle of the outlet portion with respect to a tangential direction on an outer periphery of said side plate lies from about 40 degree to about 60 degree.
Also, according to the present invention, there is provided a centrifugal fan runner, as defined in the above, wherein further each of the backward blades is formed in a wing-like shape in an inlet portion thereof.
Also, according to the present invention, there is provided an air cleaner, comprising the centrifugal fan runner as defined in the above. Further, according to the present invention, there is also provided an air cleaner, comprising the centrifugal fan runner as defined in the above, wherein further a vane for collecting stationary pressure is provided on an outlet side of said centrifugal fan runner in a main body case thereof.